A Single-way combat area, also known as a Single combat area, is an area of the RuneScape world where a player or monster can be attacked by only one player or monster at a time. Most areas of the world are single-way combat. Those that are not are Multicombat areas, where a player or monster can be attacked by several players or monsters at a time. Multicombat areas are identified by an icon of two crossed swords which appears in the top right hand corner of the interface or under the minimap. If this icon is not present, then the area is single-way combat.
Summoning familiars cannot assist the player in combat in single-way combat areas, since a player and the familiar both fight one enemy.
In extremely rare circumstances, it is possible that two people can hit the same monster with perfect timing in single-way combat.
Dreadnips, which are not familiars, can fight the same opponent as the player in a single-way area. Similarly, a Death spawn called up by a Nechryael in a single-way combat area can fight the same opponent as the Nechryael.